Means for inactivating pathogenic agents on surfaces, instruments and in contaminated fluids

ABSTRACT

The invention relates to ecologically-acceptable agent for treating pathogenic germs on surfaces, instruments and in fluids, comprising synergistic mixtures of aromatic hydroxybenzoic acids and phenols with a broad spectrum of action. The above is active against hydrophilically-sheathed and -unsheathed viruses as well as lipophilic bacteria and yeasts and is thus applicable in medicine, industry and commercial animal raising.

BACKGROUND OF THE INVENTION

Infections acquired by patients in hospitals and other medicalestablishments cause great damage to the community of insured and to thenational economy. These infections, called nosocomial diseases, havebeen attributed in the past, predominantly to bacteria.

SUMMARY OF THE INVENTION

On one hand, this has been due to the fact that in the absence ofadequate medical diagnostics, many diseases having a mycological orviral genesis have not been recognized. On the other hand, infectionscaused by viruses and fungi have increased as a result of moderntherapeutic measures and also as a result of travel and globalinterconnections; for instance, epidemics witnessed in more recent timesin European animal husbandry such as mouth-and-foot disease, Aujeszky'sdisease, and swine fever, without any exception had a viral genesis. Inhospitals, viral infections such as those due to the Norwalk-likeviruses, rotaviruses, and adenoviruses, but also fungal infectionsleading to systemic mycoses and secondary infections, are diagnosedincreasingly.

This new situation, and the new knowledge, have had the effect that inrecent years, prophylactic measures such as procedures of disinfectionmust be reconsidered and conceived in a new way. Thus, a number ofstandardizing authorities demand that apart from bacteria, disinfectionshould also extend to particularly resistant fungi (e.g., Aspergillusniger) and viruses (e.g., poliovirus and adenovirus).

Disinfectants that are broadly applicable and have sufficient viricidaleffectiveness are nowadays used in a very limited way only, the reasonbeing side effects of the agents. This is particularly true for thealdehyde-type active agents, e.g., formaldehyde, glutaric dialdehyde,succinic dialdehyde, or glyoxal and their derivatives giving offaldehydes.

Up to now these components were regarded as the classical vectors of abroad antimicrobial and antiviral effectiveness in disinfectantformulations.

Formaldehyde and glutaric dialdehyde, which are the agents mostuniversally applicable for fighting pathogenic agents owing to, amongstother reasons, the lack of technical problems in their application, havebeen classified as toxic and are suspected of being carcinogenic.Comparable characteristics are assumed to exist with the otheraldehydes.

This causes users considering the potential risks to largely do withoutaldehyde-based disinfectants.

Other active agents that are available are not effective, or are onlyeffective in a limited way, against unsheathed viruses and certain kindsof fungi, because of the particular resistance of these targets, or canonly be used in a restricted way because of their unfavorable chemicaland physical properties.

This holds true for the class of per compounds, for iodine, substancesgiving off chlorine, alcohols, cationic surfactants, amphotericsurfactants, phenols, bases, acids, and compounds giving off activeoxygen.

The peracids for instance have a very highly diversified spectrum ofantimicrobial action, but can be applied in a very limited way onlyowing to their extreme corrosivity. Considerable problems arise inaddition from the lack of stability of this compound class.

While looking for an adequate alternative it has now been foundsurprisingly that the gap that had arisen may be closed when usingcertain mixtures consisting of aromatic hydroxycarboxylic acids andphenols, not only on account of the microbicidal effectiveness but alsoon account of the favorable toxicological and ecotoxicologicalproperties and a favorable compatibility with materials.

Subject matter of the present invention are agents for the inactivationof pathogenic germs (bacteria, fungi, and viruses, sheathed andunsheathed) that can be applied to surfaces and instruments of all kindsas well as in contaminated fluids. The potential areas of applicationare the most diverse, e.g., in the context of hospitals, doctors'offices, production spaces of food industries and all the way to thestables of livestock breeders.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription of the Invention.

DETAILED DESCRIPTION OF THE INVENTION

A synergistic action between the components of the disinfectant mixturesaccording to the invention has been demonstrated, not only for theviricidal properties but also for the bactericidal and fungicidalproperties. The enhancement of bactericidal and fungicidal action wasall the more surprising inasmuch as for the phenols and aromatichydroxycarboxylic acids used, excellent antimicrobial effects hadalready been known for the individual components.

Another remarkable feature is the unusual breadth of the spectrum ofactivity, which can be seen from the fact that the inactivation ofhydrophilic Picorna viruses is just as reliable as the killing oflipophilic fungi.

The examples and tables reported in the following serve to explain thepresent invention and to prove the synergism between the synergistsaccording to claim 1.

According to F. C. Kull and P. C. Eisman, Applied Microbiology, 9,538–541 (1946), a synergism can be regarded as proven when a result ofF<1 is calculated with the following formula:F=QA/Qa+QB/Qb,where the symbols have the meaning:

F < 1 Synergism F = 1 Additive effect F > 1 Antagonism Qa = quantity ofA alone to end point Qb = quantity of B alone to end point QA = quantityof A in the mixture with B QB = quantity of B in the mixture with A.

EXAMPLES Example No. 1

Alkyl aryl sulfonate Na 12.0 parts by weight Butyl monoglycol sulfonateNa 5.0 4-Chloro-3-methylphenol 15.0 Phosphonobutanetricarboxylic acid1.5 2-Propyl alcohol 30.0 Water deionized 36.5

Example No. 2

Alkyl aryl sulfonate Na 12.0 parts by weight Butyl monoglycol sulfonateNa 5.0 2-Hydroxybenzoic acid 6.0 Phosphonobutanetricarboxylic acid 1.52-Propyl alcohol 30.0 Water deionized 45.5

Example No. 3

Alkyl aryl sulfonate Na 12.0 parts by weight Butyl monoglycol sulfonateNa 5.0 4-Chloro-3-methylphenol 15.0 2-Hydroxybenzoic acid 6.0 2-Propylalcohol 30.0 Phosphonobutanetricarboxylic acid 1.5 Water deionized 30.5

Example No. 4

Alkyl sulfonate Na 10.0 parts by weight Cumenesulfonate Na 3.02-Phenylphenol 15.0 β-Resorcinolic acid 7.0 Formic acid 5.0 2-Propylalcohol 33.0 Water deionized 27.0

Formulation Examples Nos. 1 to 3 were used to prove the synergisticeffect concerning viricidal properies with the combinations according tothe invention.

The unsheathed hydrophilic Picorna virus Polio Sabin LSc-2ab served asthe test criterion. In the testing procedure and method, the rules ofthe preliminary European standard WI 216026 (phase2; step1) werefollowed.

Experimental Conditions:

Temperature 10° C. ± 1° C. Contact time 30 min ± 10 s Protein load 3 gbovine serum albumin and 10 g yeast extract per liter

Unless pointed out otherwise, all numbers reported in the Table signifythe infection titer (log ID₅₀, ml⁻¹) after a 30-min period of action;—means no longer detectable.

TABLE 1 (Polio Sabin) Concentrations (%) Sample Control 2% 3% 4% 5% 6%7% Example No. 1 7.7 6.9 6.3 5.8 4.3 3.9 3.0 Example No. 2 7.3 6.2 5.54.3 3.8 2.8 2.3 Example No. 3 7.8 3.6 2.1 — — — —

A result can be interpreted as sufficiently effective when the infectiontiter is reduced by four logarithmic steps, ie, when a 99.99% reductionof infectivity has been attained.

It follows from Table 1 that in Example 1, the phenol component waseffective in an applied concentration of 7%, while in Example 2, thehydroxybenzoic acid had a sufficiently strong effect at a concentrationof 6%. The mixture of the two components used in Formulation example No.3 revealed a sufficiently strong inactivation of the poliovirus, alreadyat a concentration of 2%.

Substituting these results into the formula of Kull and Eisman, we find:F=2×0.06/6×0.06+2×0.15/7×0.15=0.62.

The numerical value of 0.62 thus yields unambiguous proof for thepresence of a synergistic effect.

(Substituting the percent quantities of the active agents from theformulation examples into the equation produces a constant factor of 1,and hence is superfluous for the calculation.)

A synergistic effect in fungicidal effectiveness could be demonstratedin the instance of the particularly resistant Aspergillus niger.

The tests were conducted with the quantitative suspension test accordingto DIN EN 1650 (phase2; step1).

Experimental Conditions: DIN EN 1650

A germ count reduction by four logarithmic steps constitutes therequired proof of effectiveness.

The test results are reported in Table 2. The numerical values giventhere are the logarithms (log₁₀) of the reduced germ counts; thedifference between these counts and the original germ count yields thereduction factor.

TABLE 2 (Asp. niger) Test solution log Concentrations (%) Examples (germcount/ml) 0.25% 0.5% 1% 2% 1 7.67 4.9 3.8 3.1 2 7.67 5.2 4.2 2.8 3 7.672.1F=0.25/1+0.25/1=0.50.

The above result of calculation from the data of Table 2 demonstratesthat here, too, a synergistic effect of the mixture of active agents ispresent.

The proof for synergistically effective properties against bacteria wasobtained in a quantitative suspension test according to DIN EN 1276(phase2; step1) with a Gram-positive and a Gram-negative test organism.

Experimental Conditions: Period of Action: 20 min at 20° C. ProteinLoad: 3.0 g Bovine Serum Albumin Per Liter.

Table 3 shows the results obtained with Escherichia coli.

TABLE 3 (E. coli) Concentrations (%) Examples Log (germ count/ml) 0.25%0.5% 1% 2% 1 8.49 4.63 4.1 2 8.49 5.15 4.9 2.9 3 8.49 3.16F=0.25/0.5+0.25/1=0.75.Table 4 shows the results obtained with Staphylococcus aureus.Experimental Conditions: DIN EN 1276

TABLE 4 (Staph. aureus) Concentrations (%) Examples Log (germ count/ml)0.25% 0.5% 1% 2% 1 8.4 5.9 4.8 3.3 2 8.4 6.3 5.5 4.9 2.8 3 8.4 5.1 3.17

A germ count reduction by four logarithmic steps represented therequired proof of effectiveness.F=0.5/1+0.5/2=0.75.

The microbiological results needed to prove synergism could be obtainedin all the tests, which demonstrates that the formulations according toclaim 1 of the invention are synergistically effective against bacteria,fungi, and viruses.

The formulation according to Example No. 4 and the Mycobacterium aviumAv 56 served to obtain proof of a tuberculocidal effect in the germcarrier test. The test conditions matched the provisions of the GermanVeterinary-Medical Society for the Area of Animal Husbandry (2^(nd)edition 1998).

Germ carrier: sterilized limewood pieces (height 3 mm, length 10 mm,width 10 mm).

TABLE 5 (Mycobacterium avium) Example No. 4 Period of action [min]Concentration [%] 30 60 120 180 240 2 + + + + + 4 + + − − − 5 + + − − −6 + + − − − Formalin 3% + + − − − Growth control + + + + +

The test result presented in Table 5 shows that a 4% solution ofFormulation example No. 4 after a period of action of 120 min yields thesame effect as a 3% solution of Formalin. According to DAB 10 (GermanPharmacopoeia 10^(th) edition), Formalin contains 35 to 37% formaldehydein water and 10% methanol, which corresponds to an effectiveconcentration of about 1.1% aldehyde.

In the formulation according to Example No. 4, 15%+7% of an effectivemixture of substances are present, of which 4% are employed, whichcorresponds to an effective concentration of the active agent of only0.88%.

Formalin is the generally recognized reference and scale in germ carriertests on limewood, since the relatively small aldehyde molecule willparticularly well penetrate into the fissured and disintegrated fiberstructure of the limewood carrier, and act there.

The result of the tuberculocidal effectiveness test underlines, justlike the other results, that the present invention meets all conditionsfor being able to replace aldehyde-based disinfectant formulations.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present invention andwithout diminishing its intended advantages. It is therefore intendedthat such changes and modifications be covered by the appended claims.

1. A method for the control and inactivation of pathogenic germs onsurfaces and instruments of medical and technical establishmentscomprising the step of contacting the surface or instrument with adisinfectant composition comprising: an effective microbicidal andantiviral combination of A) at least one acid selected from the groupconsisting of aromatic monohydroxycarboxylic acids, dihydroxybenzoicacids, trihydroxybenzoic acids and mixtures thereof, B) phenols; and C)one or more surfactants selected from the group consisting of i) ananionic surfactant selected from the group consisting of alkylsulfonates, alkyl aryl sulfonic acid, alkyl aryl sulfonates, alkyl arylether sulfates with 1 to 3 EO groups, alkyl ether sulfates with 1 to 3EO groups, their sodium, potassium, and ammonium salts with primary orbranched chains having a length of C₈ to C₁₈ and mixtures thereof; andii) a nonionic surfactant selected from the group consisting of alkylpolyethyleneglycol ethers with 3 to 11 EO groups and mixtures thereof,wherein the weight ratio of component (C) to components (B+A) is between1:9 and 9:1 and their sum is between 10 and 60%, referring to the totalweight of the concentrated disinfectant formula.
 2. The method accordingto claim 1, wherein the disinfectant composition further comprises atleast one component selected from the group consisting of: i) ahydrotropic agent selected from the group consisting of butyl monoglycolsulfate, cumenesulfonate, toluenesulfonate, xylenesulfonate, theirsodium, potassium, or ammonium salts thereof, and mixtures thereof; ii)a solvent selected from the group consisting of aliphatic alcohols,glycols having a chain length of C.sub.2 to C.sub.12, or mixturesthereof; and iii) a pH regulator selected from the group consisting ofaliphatic carboxylic acids, hydroxycarboxylic acids having a chainlength of C.sub.1 to C.sub.6, or mixtures thereof.
 3. The methodaccording to claim 2 wherein the weight of the hydrotropic agents andtheir salts, individually or in their mixture, is between 5 and 40% byweight, referring to the total weight of the disinfectant composition.4. The method according to claim 2 wherein the weight of the alcohols,individually or in their mixture, is between 5 and 60% by weight,referring to the total weight of the disinfectant composition.
 5. Themethod according to claim 1 wherein the disinfectant composition furthercomprises between 1 and 8% by weight of at least one sequestering agentselected from the group consisting of aminoacetic acids, phosphonicacids, their derivatives and mixtures thereof.
 6. The method accordingto claim 1 wherein the antiviral combination is in an aqueous, dilutesolution containing between 0.5 and 10% by weight of the disinfectantcomposition.
 7. The method according to claim 1 wherein the phenols areselected from the group consisting of 2-isopropyl-5-methylphenol, 2-,3-, or 4-methylphenol, hexylresorcinol, 2-phenylphenol, 2-methoxyphenol,3-methyl-4-chlorophenol, 3,5-dimethyl-4-chlorophenol,2-benzyl-4-chlorophenol, and mixtures thereof.
 8. The method accordingto claim 1 wherein the aromatic monohydroxycarboxylic acid is selectedfrom the group consisting of 2-; 3-; 4-hydroxybenzoic acid and mixturesthereof.
 9. The method according to claim 1 wherein the dihydroxybenzoicacids are selected from the group consisting of 2,3-; 2,4-; 2,5-; 2,6-;3,4-; and 3,5-dihydroxybenzoic acid and mixtures thereof.
 10. The methodaccording to claim 1 wherein the trihydroxybenzoic acid is selected fromthe group consisting of 2,3,4-trihydroxybenzoic acid,2,4,6-trihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid and mixturesthereof.
 11. A method of preparing a product for use as a disinfectantfor the control and inactivation of pathogenic germs comprising thesteps of producing a mixture comprising: an effective microbicidal andantiviral combination of A) at least one acid selected from the groupconsisting of aromatic monohydroxycarboxylic acids, dihydroxybenzoicacids, trihydroxybenzoic acids and mixtures thereof, B) phenols; and C)one or more surfactants selected from the group consisting of i) ananionic surfactant selected from the group consisting of alkylsulfonates, alkyl aryl sulfonic acid, alkyl aryl sulfonates, alkyl arylether sulfates with 1 to 3 EO groups, alkyl ether sulfates with 1 to 3EO groups, their sodium, potassium, and ammonium salts with primary orbranched chains having a length of C₈ to C₁₈ and mixtures thereof; andii) a nonionic surfactant selected from the group consisting of alkylpolyethyleneglycol ethers with 3 to 11 EO groups and mixtures thereof,wherein the weight ratio of component (C) to components (B+A) is between1:9 and 9:1, and their sum is between 10 and 60%, referring to the totalweight of the concentrated disinfectant formula.
 12. The methodaccording to claim 11, wherein the disinfectant composition furthercomprises at least one compound selected from the group consisting of: asalt selected from the group consisting of butyl monoglycol sulfate,cumenesulfonate, toluenesulfonate, xylenesulfonate as sodium, potassium,or ammonium salt and mixtures thereof; one or more aliphatic alcohols orglycols having a chain length of C₂ to C₁₂; and a pH regulatorcomprising one or more aliphatic carboxylic acids or hydroxycarboxylicacids having a chain length of C₁ to C₆.
 13. The method according toclaim 11 wherein the weight ratio of the component (A) to component (B)is between 1:9 and 9:1.
 14. The method according to claim 11 wherein thedisinfectant composition further comprises between 1 and 8% by weight ofat least one sequestering agent.
 15. The method according to claim 11comprising the step of preparing an antiviral combination containingbetween 0.5 and 10% by weight of the disinfectant composition.
 16. Themethod according to claim 11 wherein the phenols are selected from thegroup consisting of 2-isopropyl-5-methylphenol, 2-, 3-, or4-methylphenol, hexylresorcinol, 2-phenylphenol, 2-methoxyphenol,3-methyl-4-chlorophenol, 3,5-dimethyl-4-chlorophenol,2-benzyl-4-chlorophenol, and mixtures thereof.
 17. The method accordingto claim 11 wherein the aromatic monohydroxycarboxylic acid is selectedfrom the group consisting of 2-; 3-; 4-hydroxybenzoic acid and mixturesthereof.
 18. The method according to claim 11 wherein thedihydroxybenzoic acids are selected from the group consisting of 2,3-;2,4-; 2,5-; 2,6-; 3,4-; and 3,5-dihydroxybenzoic acid and mixturesthereof.
 19. The method according to claim 11 wherein thetrihydroxybenzoic acid is selected from the group consisting of2,3,4-trihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid,3,4,5-trihydroxybenzoic acid, and mixtures thereof.
 20. A method for thecontrol and inactivation of pathogenic germs on surfaces and instrumentsof medical and technical establishments comprising the step ofcontacting the surface or instrument with a disinfectant compositioncomprising: an effective microbicidal and antiviral combination of A) atleast one acid selected from the group consisting of aromaticmonohydroxycarboxylic acids, dihydroxybenzoic acids, trihydroxybenzoicacids and mixtures thereof, B) phenols; and C) one or more surfactantsselected from the group consisting of i) an anionic surfactant selectedfrom the group consisting of alkyl sulfonates, alkyl aryl sulfonic acid,alkyl aryl sulfonates, alkyl aryl ether sulfates with 1 to 3 EO groups,alkyl ether sulfates with 1 to 3 EO groups, their sodium, potassium, andammonium salts with primary or branched chains having a length of C₈ toC₁₈ and mixtures thereof; and ii) a nonionic surfactant selected fromthe group consisting of alkyl polyethyleneglycol ethers with 3 to 11 EOgroups and mixtures thereof, wherein the weight ratio of component (C)to components (B+A) is between 1:9 and 9:1, and their sum is between 5and 40%, referring to the total weight of the concentrated disinfectantformula.